BT 500va Mains Conditioning Unit off EBay
Has to be (£40) the best cost effective improvement I have made in over 30 years!
Seeing that I already had a 'Mains Spur', Tacima CS929, Russ Andrews Classic Powerkords all plugged in I didn't think there would be more to come cleaning the mains any further.
Boy was I wrong, my system sounded really good before but deep base became more musical, even more background detail came out throughout all the range as well.
Can recommend all of the above mods, plus of course Blue Tack!